Suppose two students are taking a math test. Suppose that for a particularly difficult problem one student writes "7" as the solution and the other writes "65000*pi/sqrt(3)". It is reasonable to conclude that at least one of the two students got the problem wrong. Is it also reasonable to conclude that at least one of the students must be an idiot? No.
Does it mean they can't be friends? Of course not. (They might have difficulty collaborating on an engineering project that uses the same techniques as the math problem, but that's not the only thing in life.)
Is it reasonable to conclude that the two solutions are equally valid or equally likely? Not necessarily, but it depends on the problem (both solutions may be completely and obviously wrong).
As you've probably guessed, all of this is to explain how I can consider myself a strong atheist and at the same time caution against dismissing religious people as stupid, closed-minded, or willfully ignorant.
Why do I think my conclusion about God(s) is right?
Imagine there's a street sign near my house that I pass every day. Imagine that one day there's a bright red political sticker sticking to the middle of it that wasn't there before. I don't know how it got there, but I can make some conjectures:
1. Some person came by and put it there.
2. A race of sentient bats made the sticker and stuck it there (but no one has ever seen them because they're invisible).
3. The sticker was actually applied at the factory when the sign was made, but it just wasn't visible until recently because it was made with a new technology of perfectly invisible stickers that become visible after a fixed length of time.
4. The sign and sticker don't exist -- I'm really just a brain in a jar, and my entire reality is an illusion.
To me, choice #1 is the reasonable conclusion, and I would feel very confident that it is the correct answer -- it conforms with experiences and observations. I don't think that #2 or #3 is rational conclusion, even though I can't disprove either one. I would be willing to reconsider my rejection of #2 or #3 if someone showed me evidence that the species (resp. new technology) exists. I think Greta Christina covered the solipsism argument (#4) pretty well. I'll just add that I've never met anyone who seriously believes that the solipsistic model of the universe is correct -- it's typically just thrown out there to bolster the post-modernist argument that we can't be sure of anything, so theories contradicted by evidence are just as reasonable as theories that are consistent with evidence.
This is the reason I feel completely confident in my conclusion that God(s) -- as typically defined by humans -- do(es) not exist.
I also know that if you are religious, you probably disagree with my second parable and/or my interpretation of it. That's fine -- I'm not trying to debate you on your perception of the universe. I'm just explaining what it looks like to me.
Around the Internet, I see a lot of people trying to explain away people who disagree with them. There's a whole lot of "those guys just won't listen to reason because..." These assessments are essentially always wrong (in my humble opinion). Or to be more precise, I think they're a little bit right mixed with a whole lot of wrong. In my experience, most people have many complex reasons for believing as they do, and what's more, just because two people have reached the same conclusions it doesn't mean that their character, motivations/biases, or even their reasoning style is the same.
It is false to say that all people who believe X are closed-minded and refuse to listen to anything but what they want to hear. It is false to say that all people who believe X have failed to think critically about their beliefs. It is also a fallacy to confuse confidence in a conclusion with closed-mindedness: Just because you've analyzed a question and feel confident that your conclusion is right, that doesn't mean you wouldn't consider new evidence and new arguments.
So in short I recommend critical thinking and sincere introspection (for everyone, me included). And I'm not going to look at your answer and from there presume to tell you how you reached it.